Melissopalynological and biochemical evaluation of the authenticity of Apis melifera adansonia honeys obtained from five states of Nigeria

Abstract

The study was conducted to determine the pollen composition, diversity and biochemical constituents of honey samples from five states of Nigeria. A total of 104 pollen types belonging to 57 plant families were recorded. The honey samples were classified into three botanical groups on basis of major contributing plants; Unifloral, bifloral and polyfloral honeys. Shannon-Wiener Diversity and Pielou’s Evenness Indices ranged from 1.987 – 2.676 and 0.580 – 0.705 respectively indicating high plant heterogeneity foraged by the honeybees. The common plant sources of nectar and pollen include CombretaceaeMelastomataceae, Phyllanthus muelerianus, Elaeis guineensis, Alchornea cordifolia and Syzygium guineense. The biochemical analyses conformed to the Codex and EU Council standard for all parameters tested except moisture content from Akpanya and Anyigba samples that exceeded the limit. The highest crude protein content was recorded in Calabar sample (1.71 ± 0.01 %) while ash content was highest in Anyigba (0.29 ± 0.02 %). Calabar and Akpanya samples had the highest fibre value (0.80 ± 0.01 %). The hydroxymethylfurfural value was highest in Abakaliki (4.46 ± 0.02 mg/kg). Sample from Calabar had the highest free acidity (0.12 ± 0.01 meg/kg), while electrical conductivity was highest in Akpanya (17.70 ± 0.01 µS/cm) sample. The pH and refractive index values, 4.72 ± 0.01 and 1.50 ± 0.01 respectively were highest in Abakaliki sample. The sum of fructose and glucose ranged from 68.8 ± 0.01 – 82.62 ± 0.01 % in the samples and had ratios greater than one in the samples making them subject to low crystallization.

Keywords: Pollen analysis, Biochemical constituents, Honey, Pollen diversity